Flexible pitman head



Feb. 14, 1928. 1,659,000

' C. PEARSON FLEXIBLE PITMAN HEAD Filed- July 1 1925 g TV V v V Patented Feb. 14, 1928;

UNITED STA S oiiARnns i nnnson', on o ri oeeo, innmois nssiqiiion To rnrnitmirioniin HAIR-V i VESTER COMPANY, A oonron er on on NEW, JERSEY.

FLEXIBLE PITM enirEAD.

Application filed Jilly 1, 1925. Serial N0. 40,712.

This invention pertains generally to pitconnections and more particularly to a pitrnan connection adapted for usein con,- nection with' mowing machines andthe like.

Mowing machines, as now known in the art; embodying a reciprocetory cutter bar, have such cutter bai's.1provided-with aeocalled knife head and this knife h} d is provided with a bearing nieinberwhich is coupled by means of a pitnian to a crank or Wrist pin carried by acranlc dist: fly wheel tilted to e driving shaft. is aisual in these constructions;during normal operation on an even field, this crank pin is in parallel alineinent with the longitudinal axis of the mowing'innchine and lies substantially in a; horizontal plane. Thelznite or cutter bar in its normal position of adjustment is reciproeated in aidirection transversely or perpendicularly of the line of draft. These,

pitmen areisornetimes ofa rigid construe hasbeen overcome to some extent in the provision of a pivotedor jointed upper end construction; (but suchzjointed upper end is likewise objectionablees the strains of use soon causestvearand, breakage. i

An object of the present invention to overcome the difliculty by some means other than by a pivoted or jointed ripper end constrii'citioii and toipr'ovidea pitman which will be non-jointed and flexible under strain in certain directions but will be rigid and inflexible under strains in other directions.

Another object is to provide a pitman construction of the kind specified, the upper end of which will be non-jointed and of simple construction and which may be readily manufactured for commercial use at a minimum of expense.

skilled in this loosening thereof,

aiiurther object to provide i111- proved bearing box forsuch airpitinan ern- V bodying a'novel means for, preventing unlooseiiing ottlieparts comprising said beer 7 ingibo xiy. I i i X a n Other [obj ect-s. will be, apparent to those art as the description hereof progresses;

Briefly; the objects of ithis invention are accomplished in thelprovision of the usual wooden pit-manbod nheving a flat, flexible, nonointed metallic extenslon secured'theree to atone end, sa d extens on carrying et-its free end at a point spacedgfroin the body oi the pit-i'nrrn a two part bearing boss, said parts being interlocked and having disposed therebetween a means for preventing un- In the accompanying sheet of drawinsi wherein the-preferred en1bodin1ent of t i invention has been illustrated wherein like characters of reference, designate Sin r-pflr l a r Fig. l is a plan view of that end of the pitinan which isconhected to the crank disk err fly W e fge m er ;I

Fig 2, isasiniilarviewshowing the bean ing box in sectioii when viewed along the line -221 in the directionl of the arrows shown in Fig. 3; r i

Fig; 3 is aside view of the construction she ei l s' el n liligxtis nend Fi 5. s me i i ile Tie Fi but shown section esviewed alon 5f5- shown n F g. 1; and

the 11m view, of the bearing v.lliigggi'i 1s a plan viewiof the novellocking nieansntili edlin thisci vention f' v j v As shown 111, he draw ngs, the eontein tionalwooden body lOjo'i' s pitina'n is shown; the-gripper end of which is slitted {for the reception of a flat inettillic andfpreferably steel;- ext'ens'ion 11, sitid ,eziteii'sionlbeiiigi securely fiiedto the body eplurality of i The ,flatestensie 11 istapered assliown, whereb the sanie is capable of having agi'adiintedresiliency,*as will be iniderstood. The free end of the flat member 11 is apertured to receive a novel form of bearing box in which is journaled, as is usual in this'art, the crank pin carried by the crank disk mounted on the mower drive shaft. i f

This bearing box is made up of two pieces, one of the pieces being a sleevedike merhber Kai-ii 18 having a threaded bore conforming subilurthern'iore having a polygonally shaped nut or wrench engaging portion 16.

shown, the member 13 has an upstanding bored out boss 17, which isadapted to be provided with any conventional appliance for applying lubricant to the bearing box.

The two pieces 13 and 1% are also formed to provide an annular lubricantcontaining chamber 18 in communication with the bore in the boss 1'7, said chamber 18 com1nunieating with the interior of the bearing'box and the wrist pin journaled therein, by means of apertures 19. The'boss 17 is provided on its upper end, and in-a direction extending toward the member 1 1, with a small shoulder 20 for a purpose to be presently described.

Due to the severe use to which a bearing box of this kind is subjectechit is quite unlikely that the threaded engagement between the two pieces making up the bearing box will be sufficient to secure the parts together and there is, therefore, provided a novel form of locking means in the form of a washer for insuringa positive retention of the parts forming the bearing box in proper position. This locking means is in the form of a washer indicated generally at 21, as shown in Fig. 6, the same being centrally apertured and having two wings 22 on its upper side and a plurality of segmental flaps 23 arranged along the remainder of its periphery, as shown. Before securing the piece 14: into the piece 13, this look washer is placed in position, as shown in Fig. 5, against the flat extension with the flaps 22 bent back to straddle the boss 17 on each side of the shoulder 20. The parts 13 and l tare then screwed together clamping the washer therebetween, thus providing a means which will prevent rotation of the nunnber 13; The member 14, by means of a wrench, may then be tightened as far as possihle, so that one of the flaps 23 will be in a p0... ion to be folded backwardly in a direction to engage one of the polygonal faces of the wrench engaging portion 16, thereby preventing rotation of the member 14 and unloosening thereof. It will thus'be appreciated that the lock washer, which is made of easily bendable material and in the form of a stamping, is provided with means which. may be oppositely disposed to lock the oppositely disposed pieces of the bearing box and thereby prevent relative rotation of the'parts with respect to each other.

Due to the construction of the extension 11, as above described, it will be seen that a construction has been provided by means of which a lateral flexing of the pitman is permitted, but a flexing at right angles to this direction is prevented. The metallic strip 11 is purposely made wider at its end adjacent the bearing box to prevent any flexing in a horizontal plane parallel to the line of draft, whereas any lack of alinement between the crank pin and the knife head, as when the cutter bar is tilted, is compensated for by the flexible connection. As there are no moving parts, that-is, as this upper end is non-jointed, there can be no friction and wear to cause breakage.

lVhile in the above specification only the preferred embodiment of this invention has been shown and described, it is to be understood, of course, that the same is capable of modification and changes, and, therefore,

changes in the construction and arrangement of parts may be made withoutdeparting from the spirit and scope of this invention as expressed hereinafter in the claims.

Vhat is claimed is:

1. In a pitman comprising a body and a flat, flexible, metallic extension secured to one end thereof, the combination of a hearing box made of two parts screw threaded together and clamping the extension between them to mount the box, and means causing oil to be circulated in the interior of the box.

2. In a pitman comprising a body and a flat, flexible, metallic extension secured to one end thereof, the combination of a bearing box comprising two parts screw threaded together and clamping the extension between them to mount the box, means preventing accidental rotational relative loosening movementbetween the parts, and means causingoil to be freely circulated in the interior of the box.

In testimony whereof I affix my signature.

CHARLES rnanson. 

